Haloalkoxide-substituted phosphazene polymers are useful in many applications because of their flame resistance, low temperature flex properties and high temperature stability. Of these, most interest has been in the fluoroalkoxide-substituted polyphosphazene. Such compositions are disclosed in U.S. Pat. Nos. 3,515,688 and 3,700,629. Other fluoroalkoxides-substituted phosphazene polymers are disclosed in U.S. Pat. Nos. 3,702,833, 3,732,175, 3,838,073, 3,844,983, 3,888,799, 3,888,800, 3,896,058, 3,943,088, 3,945,966, 3,948,820, 3,970,533, 3,972,841, 4,000,166, all of which are incorporated herein by reference for their disclosure of the prior methods of making alkaline metal fluoroalkoxides and the use of such fluoroalkoxides in preparing polyphosphazene polymers and the utility of such polyphosphazene polymers.
In U.S. Pat. No. 3,515,688, the sodium fluoroalkoxide used to make the fluoroalkoxide-substituted phosphazene polymers was prepared by reacting metallic sodium directly with the fluorine-substituted alcohol. Pieces of metallic sodium, which were cut and weighed under dried benzene, were added directly to the fluorine-substituted alcohol and the mixture stirred overnight following which it was refluxed to complete the reaction. A hazard associated with a process carried out in this manner is that the metallic sodium in addition to reacting with the alcohol hydroxyl groups can also react with the halogen bonded to the alcohol. Such reactions can become very exothermic and lead to eruption of the reaction contents from the reaction vessel and can ignite. Attempts to prepare sodium alkoxides of fluorine-substituted alcohols using sodium dispersed in toluene were not successful because the sodium dispersion initially made in toluene tended to coalesce.
Fluoroalkoxide-substituted polyphosphazenes containing a few random o-allylphenoxide substituents are described in Kyker, et al, U.S. Pat. No. 3,970,533. The allylphenoxide groups impart cross-linking properties to the elastomer permitting them to be cured using curing agents such as peroxide or sulfur. Kyker, et al made these products by adding a mixture of fluoroalcohols and o-allylphenol to sodium metal in dry tetrahydrofuran. The sodium fluoroalkoxide o-allylphenoxide solution which resulted was added to a benzene solution of linear phosphonitrilic chloride polymer.